Diff: Arduino-mbed-APIs/arduino-d21.cpp

Revision:

77:7f227a4dffe6

Child:

78:9d2cc07d9525

diff -r 79f8ca9c8025 -r 7f227a4dffe6 Arduino-mbed-APIs/arduino-d21.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Arduino-mbed-APIs/arduino-d21.cpp	Mon Jul 31 16:11:17 2017 +0200
@@ -0,0 +1,398 @@
+/*
+ * The file is Licensed under the Apache License, Version 2.0
+ * (c) 2017 Helmut Tschemernjak
+ * 30826 Garbsen (Hannover) Germany
+ */
+
+#ifdef ARDUINO
+
+using namespace std;
+
+#include "arduino-mbed.h"
+#include "arduino-util.h"
+
+
+
+#if defined(__SAMD21G18A__) || defined(__SAMD21J18A__)
+/*
+ * __SAMD21J18A__ is the SamD21 Explained Board
+ * __SAMD21G18A__ is Genuino Zero-Board (compatible with the LoRa board)
+ */
+
+/*
+ * see tcc.h is automatically included from:
+ * Arduino15/packages/arduino/tools/CMSIS-Atmel/1.1.0/CMSIS/
+ * Device/ATMEL/samd21/include/component/tcc.h
+ * See also tcc.c (ASF/mbed, e.g. Tcc_get_count_value)
+ */
+static void initTimer(Tcc *t);
+static uint32_t getTimerCount(Tcc *t);
+
+/*
+ * The Atmel D21 has three TCC timer, other models have more.
+ */
+const struct TCC_config {
+    Tcc *tcc_ptr;
+    IRQn_Type tcc_irq;
+    uint8_t nbits;
+} TCC_data[] {
+    { TCC0, TCC0_IRQn, 24 },
+    { TCC1, TCC1_IRQn, 24 },
+    { TCC2, TCC2_IRQn, 16 },
+    { NULL, (IRQn_Type)NULL, 0 }
+};
+
+/*
+ * We preferably use the TCC timers because it supports 24-bit counters
+ * versus TC Timer which supports only 8 or 16 bit counters only.
+ * TCC0/1/2 timer work on the D21 using Arduino Zero.
+ */
+#define USE_TCC_TIMEOUT	0 // 0=TCC0, 1=TTC1, 2=TTC2 (see TCC_data)
+#define USE_TCC_TICKER	1
+
+
+/*
+ * every 21333 ns equals one tick (1/(48000000/1024)) // prescaler 1024, 48 MHz
+ * every 61035 ns equals one tick (1/(32768/2))		  // prescaler 2, 32 kHz
+ * COUNT*DIVIDER*SECS until interrupt
+ * CPU 48 MHz = (65536*1024)/1.398636s
+ * RTC 32 kHz = (65536*2)/4.0s
+ */
+#define NS_PER_CLOCK_CPU	21333 // ns secs per clock
+#define NS_PER_CLOCK_RTC	61035 // ns secs per clock
+
+#define NS_PER_CLOCK	NS_PER_CLOCK_RTC
+
+/* ----------------- TICKER TIMER CODE ----------------------*/
+
+/*
+ * The global ns_counter contains the time in ns from the last time
+ * the counter has been wrapped. It cannot be used directly because the
+ * current counter has to be added fore using it. Use instead
+ * ns_getTicker(), us_ ns_getTicker(), ms_getTicker()
+ */
+
+uint64_t ticker_ns;
+static bool initTickerDone = false;
+
+uint64_t ns_getTicker(void)
+{
+    Tcc *t = TCC_data[USE_TCC_TICKER].tcc_ptr;
+    if (!initTickerDone) {
+        initTimer(t);
+        initTickerDone = true;
+
+        // set counter top to max 16 bit for testing
+        // t->PER.bit.PER = 0xffff;
+        // while (t->SYNCBUSY.bit.PER == 1); // wait for sync
+
+        t->CTRLA.reg |= TCC_CTRLA_ENABLE ;		// Enable TC
+        while (t->SYNCBUSY.bit.ENABLE == 1);	// wait for sync
+    }
+    
+    /*
+     * if we are called from the interrupt level, the counter contains
+     * somehow wrong data, therfore we needs to read it twice.
+     * Another option was to add a little wait (loop 500x) 
+     * in the TCC_TIMEOUT interrupt handler.
+     */
+    if (SCB->ICSR & SCB_ICSR_VECTACTIVE_Msk) // check if we are in the interrupt
+        getTimerCount(t);
+
+    uint64_t counter_us = (uint64_t)NS_PER_CLOCK * (uint64_t)getTimerCount(t);
+    uint64_t ns = ticker_ns + counter_us;
+
+    return ns;
+}
+
+#if USE_TCC_TICKER == 0
+void TCC0_Handler()
+#elif USE_TCC_TICKER == 1
+void TCC1_Handler()
+#elif USE_TCC_TICKER == 2
+void TCC2_Handler()
+#endif
+{
+    Tcc *t = TCC_data[USE_TCC_TICKER].tcc_ptr;
+    /*
+     * Overflow means the timer top exeeded
+     */
+    if (t->INTFLAG.bit.OVF == 1) {  // A overflow caused the interrupt
+        t->INTFLAG.bit.OVF = 1;    // writing a one clears the flag ovf flag
+        // ser->println("T_OVF");
+
+        /*
+         * reading the count once is needed, otherwise
+         * it will not wrap correct.
+         */
+        getTimerCount(t);
+        
+        int bits = TCC_data[USE_TCC_TICKER].nbits;
+        int maxCounts = (uint32_t)(1<<bits);
+		
+        ticker_ns += (uint64_t)NS_PER_CLOCK * (uint64_t)maxCounts;
+    }
+    if (t->INTFLAG.bit.MC0 == 1) {  // A compare to cc0 caused the interrupt
+        t->INTFLAG.bit.MC0 = 1;    // writing a one clears the MCO (match capture) flag
+        // ser->println("T_MC0");
+    }
+}
+
+/* ----------------- SUPPORT CODE FOR TCC TIMERS----------------------*/
+
+static bool initTimerDone = false;
+
+static void initTimer(Tcc *t)
+{
+    
+    /*
+     * enable clock for TCC, see gclk.h
+     * GCLK_CLKCTRL_GEN_GCLK0 for 48 Mhz CPU
+     * GCLK_CLKCTRL_GEN_GCLK1 for 32k extern crystal XOSC32K (ifdef CRYSTALLESS)
+     * GCLK_CLKCTRL_GEN_GCLK1 for 32k internal OSC32K
+     * see Arduino: arduino/hardware/samd/1.6.15/cores/arduino/startup.c
+     * Use TCC_CTRLA_PRESCALER_DIV1024 for for 48 Mhz clock
+     * Use TCC_CTRLA_PRESCALER_DIV2 for 32k clock
+     */
+    if (t == TCC0 || t == TCC1) {
+        REG_GCLK_CLKCTRL = (uint16_t) (GCLK_CLKCTRL_CLKEN | GCLK_CLKCTRL_GEN_GCLK1 | GCLK_CLKCTRL_ID_TCC0_TCC1);
+    } else if (t == TCC2) {
+        REG_GCLK_CLKCTRL = (uint16_t) (GCLK_CLKCTRL_CLKEN | GCLK_CLKCTRL_GEN_GCLK1 | GCLK_CLKCTRL_ID_TCC2_TC3_Val);
+    }
+    while (GCLK->STATUS.bit.SYNCBUSY == 1); // wait for sync
+    
+    t->CTRLA.reg &= ~TCC_CTRLA_ENABLE;   // Disable TCC
+    while (t->SYNCBUSY.bit.ENABLE == 1); // wait for sync
+    
+    t->CTRLA.reg |= (TCC_CTRLA_PRESCALER_DIV2 | TCC_CTRLA_RUNSTDBY); // Set perscaler
+    
+    t->WAVE.reg |= TCC_WAVE_WAVEGEN_NFRQ; // Set wave form configuration
+    while (t->SYNCBUSY.bit.WAVE == 1);	   // wait for sync
+    
+    t->PER.bit.PER = 0xffffff; // set counter top to max 24 bit
+    while (t->SYNCBUSY.bit.PER == 1); // wait for sync
+    
+    // the compare counter TC->CC[0].reg will be set in the startTimer
+    // after the timeout calculation is known.
+    
+    // Interrupts
+    t->INTENSET.reg = 0;              // disable all interrupts
+    t->INTENSET.bit.OVF = 1;          // enable overfollow
+    t->INTENSET.bit.MC0 = 1;          // enable compare match to CC0
+    
+    const struct TCC_config *cp = &TCC_data[0];
+    while (cp->tcc_ptr) {
+        if (cp->tcc_ptr == t) {
+            NVIC_EnableIRQ(cp->tcc_irq); // Enable InterruptVector
+            break;
+        }
+        cp++;
+    }
+}
+
+
+#if 0
+// Atmel ASF Code
+static uint32_t getTimerCount(Tcc *t)
+{
+    uint32_t last_cmd;
+    /* Wait last command done */
+    do {
+        while (t->SYNCBUSY.bit.CTRLB); /* Wait for sync */
+        
+        last_cmd = t->CTRLBSET.reg & TCC_CTRLBSET_CMD_Msk;
+        if (TCC_CTRLBSET_CMD_NONE == last_cmd) {
+            /* Issue read command and break */
+            t->CTRLBSET.bit.CMD = TCC_CTRLBSET_CMD_READSYNC_Val;
+            break;
+        } else if (TCC_CTRLBSET_CMD_READSYNC == last_cmd) {
+            /* Command have been issued */
+            break;
+        }
+    } while (1);
+    
+    while (t->SYNCBUSY.bit.COUNT); /* Wait for sync */
+
+    return t->COUNT.reg;
+}
+#endif
+
+
+static uint32_t getTimerCount(Tcc *t)
+{
+    
+    noInterrupts();
+
+    while (t->SYNCBUSY.bit.CTRLB); /* Wait for sync */
+
+    t->CTRLBSET.bit.CMD = TCC_CTRLBSET_CMD_READSYNC_Val; /* Issue read command and break */
+
+    while (t->SYNCBUSY.bit.COUNT); /* Wait for sync */
+    
+    uint32_t count = t->COUNT.reg;
+
+    interrupts();
+    
+    return count;
+}
+
+
+Tcc *getTimeout_tcc(void)
+{
+    return TCC_data[USE_TCC_TIMEOUT].tcc_ptr;
+}
+
+
+void stopTimer(Tcc *t)
+{
+    t->CTRLA.reg &= ~TCC_CTRLA_ENABLE;   // Disable TC
+    while (t->SYNCBUSY.bit.ENABLE == 1); // wait for sync
+}
+
+
+/* ----------------- TIMEOUT TIMER CODE ----------------------*/
+
+void startTimer(Tcc *t, uint64_t delay_ns)
+{
+    if (!initTimerDone) {
+        initTimer(t);	// initial setup with stopped timer
+        initTimerDone = true;
+    }
+    
+    stopTimer(t);		// avoid timer interrupts while calculating
+    
+    /*
+     * every 21333 ns equals one tick (1/(48000000/1024))
+     * COUNT*DIVIDER*SECS until interrupt
+     * 48 Mhz = (65536*1024)/1.398636s
+     */
+    uint64_t nclocks = (uint64_t)delay_ns;
+    nclocks /= (uint64_t)NS_PER_CLOCK;
+    int nCounts = nclocks;
+   
+    int bits = TCC_data[USE_TCC_TIMEOUT].nbits;
+    int maxCounts = (uint32_t)(1<<bits)-1;
+
+    if (nCounts > maxCounts) 	// if count exceeds timer capacity
+        nCounts =  maxCounts;	// set the largest posible count.
+    if (nCounts <= 0)
+        nCounts = 1;
+    t->CC[0].bit.CC = nCounts;
+    while (t->SYNCBUSY.bit.CC0 == 1); // wait for sync
+
+    t->CTRLA.reg |= TCC_CTRLA_ENABLE ; // Enable TC
+    while (t->SYNCBUSY.bit.ENABLE == 1); // wait for sync
+#if 0
+    ser->print(ms_getTicker(), DEC);
+    ser->print(" startTimer: nCounts=");
+    ser->println(nCounts, DEC);
+#endif
+}
+
+
+#if USE_TCC_TIMEOUT == 0
+void TCC0_Handler()
+#elif USE_TCC_TIMEOUT == 1
+void TCC1_Handler()
+#elif USE_TCC_TIMEOUT == 2
+void TCC2_Handler()
+#endif
+{
+    Tcc *t = TCC_data[USE_TCC_TIMEOUT].tcc_ptr;
+    uint64_t nsecs = ns_getTicker();
+    
+    /*
+     * Overflow means the max timer exeeded, we need restart the timer
+     * Interrupts and
+     */
+    if (t->INTFLAG.bit.OVF == 1) {  // A overflow caused the interrupt
+        t->INTFLAG.bit.OVF = 1;    // writing a one clears the flag ovf flag
+    }
+    
+    if (t->INTFLAG.bit.MC0 == 1) {  // A compare to cc0 caused the interrupt
+        //ser->print("MC0\r\n");
+        t->INTFLAG.bit.MC0 = 1;    // writing a one clears the MCO (match capture) flag
+    }
+
+    t->CTRLA.reg &= ~TCC_CTRLA_ENABLE;   // Disable TC
+    while (t->SYNCBUSY.bit.ENABLE == 1); // wait for sync
+    
+    for (int i = 0; i < MAX_TIMEOUTS-1; i++) {
+        struct TimeoutVector *tvp = &TimeOuts[i];
+        if (tvp->timer && nsecs >= tvp->timer->_timeout) {
+            Timeout *saveTimer = tvp->timer;
+            tvp->timer = NULL;
+            Timeout::_irq_handler(saveTimer);
+        }
+    }
+    /*
+     * we need to restart the timer for remaining interrupts
+     * Another reason is that we stopped this counter, in case there are
+     * remaining counts, we need to re-schedule the counter.
+     */
+	Timeout::restart();
+}
+
+
+/* ----------------- D21 sleep() and deepsleep() code ----------------------*/
+
+void sleep(void)
+{
+    /*
+     * If we use the native USB port our Serial is SerialUSB
+     * and if the SerialUSB and connected we should
+     * not enter into sleep mode because this kills the Arduino USB emulation
+     */
+    if (ser && ser == (Stream *)&SerialUSB) {
+        __WFI();
+        return;
+        // USB->CTRLA.bit.ENABLE = 0;
+        // USB->HOST.CTRLA.reg = 0;
+        // USB->HOST.CTRLA.bit.ENABLE &= USB_CTRLA_ENABLE;
+    }
+
+    
+#if  1 // (SAMD20 || SAMD21)
+    /* Errata: Make sure that the Flash does not power all the way down
+     * when in sleep mode. */
+    NVMCTRL->CTRLB.bit.SLEEPPRM = NVMCTRL_CTRLB_SLEEPPRM_DISABLED_Val;
+#endif
+    uint32_t saved_ms = ms_getTicker();
+    SysTick->CTRL &= ~SysTick_CTRL_ENABLE_Msk; // disbale SysTick
+    
+    SCB->SCR &= ~SCB_SCR_SLEEPDEEP_Msk;	// clear deep sleep
+    PM->SLEEP.reg = 2; // SYSTEM_SLEEPMODE_IDLE_2 IDLE 2 sleep mode.
+
+    __DSB(); // ensures the completion of memory accesses
+    __WFI(); // wait for interrupt
+    
+    int count = ms_getTicker() - saved_ms;
+    if (count > 0) { // update the Arduino Systicks
+        for (int i = 0; i < count; i++) {
+            SysTick_Handler();
+        }
+    }
+    SysTick->CTRL |= SysTick_CTRL_ENABLE_Msk; // enable SysTick
+}
+
+void deepsleep(void)
+{
+#if  1 // (SAMD20 || SAMD21)
+    /* Errata: Make sure that the Flash does not power all the way down
+     * when in sleep mode. */
+    NVMCTRL->CTRLB.bit.SLEEPPRM = NVMCTRL_CTRLB_SLEEPPRM_DISABLED_Val;
+#endif
+
+    SysTick->CTRL &= ~SysTick_CTRL_ENABLE_Msk; // disbale SysTick
+    
+    SCB->SCR |=  SCB_SCR_SLEEPDEEP_Msk; // standby mode
+    
+    __DSB(); // ensures the completion of memory accesses
+    __WFI(); // wait for interrupt
+
+    SysTick->CTRL |= SysTick_CTRL_ENABLE_Msk; // enable SysTick
+}
+
+#endif // D21 TCC Timer, sleep, etc-
+
+#endif // ARDUINO